Multi-gas appliance

ABSTRACT

Cooking appliance having an external control panel equipped with one or more regulating valves, where the rotary regulator organ is equipped with various peripheral openings for supplying a flow Q. For the supply of one or another type of gas, NG or LPG, either the control knob or a bezel disk in the external panel are interchangeable on the appliance, being chosen between two different available units, one and the other permitting two different angular position limits A 2 , A 3  of the regulator organ or the supply of a constant flow Qmin through one or another opening with calibrated sections, respectively for NG or LP gas. An appendix in the control knob guided in a slide groove on the control panel of the appliance, or a tongue on the bezel disk stopping the rotation of the control knob, determines the travel limit A 2  for the supply of Qmin of NG.

TECHNICAL FIELD

The present invention relates to a gas tap of the tapered rotaryappendix type attached to a rotary actuating shaft, being the gas tapmounted on the panel of a cooking appliance, wherein the rotary appendixis provided with a series of openings for adjusting the flow rateaccording to the fuel gas family supplied to the cooking appliance.

PRIOR ART

Gas taps of the above-defined type, provided with a dome-shaped bearingbush guiding the rotation of the actuating shaft and fulfilling at thesame time the function of a cover for the hollow tap body, are alreadyknown. The gas tap is mounted on the front control panel with theactuating shaft passing through an external control panel in theappliance, and the tap body resting inside the appliance connected to afuel gas supply tube or nipple. The external free end of the actuatingshaft is fitted with a rotary control knob inserted in the latter. Thecontrol knob is removable from the shaft by pulling it out. The hollowbody of the tap has its own gas outlet conduit which is connected to therespective appliance burner.

An example of rotary tap of the above type is disclosed inEP-0805310-A1, having its actuating shaft coupled to a frustro-conicalregulating organ, which is able to rotate a given angle for the supplyof a gas flow from two angular positions spaced around 120.degree.apart, corresponding respectively to a high or maximum flow “Qmax” andto a low or minimum flow “Qmin”, the latter applied to “gentle boiling”.The rotation of the shaft as far as one of the angular positions, isstarted from an initial valve closed “OFF” position.

In this type of known valves the actuating shaft has a pin protruding ina radial direction to limit its angular travel, guided on a circularsurface in the inner face of the body cover or some other part of thevalve body. The total travel of the regulating organ thus limited is,for instance, 210.degree. from the OFF position. The end positioncorresponds to Qmin. Any of the flows Qmax, Qint—intermediate flow—andQmin is regulated by way of a corresponding hole or groove in theregulating organ facing the outlet conduit. All the flow rates aresupplied from a common inlet conduit through an inner chamber in theregulating organ which is in communication with an outlet conduit. TheQmin outlet hole has an area of calibrated section for a standard typeof given fuel gas, adjusted according to the output power of the cookingappliance burner.

Solutions are already known for a single tap to be mounted on cookingappliances that use two different types of gas, such as natural gas (NG)or liquefied petroleum gas (LPG). For example, in U.S. Pat. No.5,009,393 an additional valve element in the form of a sleeve, isinserted in the inner chamber of the tapered regulating organ. The areaof the opening section for the passage of gas flow towards the outlet,which corresponds to low flow or minimum flow Qmin, is adjusted byrotating this added valve sleeve which thus modifies the uncoveredsection area of the outlet opening.

This known solution has the disadvantage that for adjusting the Qmin forthe rotation of the valve sleeve, it is necessary to use a screwdriver,which has to be inserted from an opening in the actuating shaft until itreaches the valve sleeve and to transmit a precise turn.

DISCLOSURE OF THE INVENTION

The object of the invention comprises a gas tap for a domestic cookingappliance of the type with a frustro-conical regulating organ coupled toan actuating shaft and to a rotary control knob, which is capable ofsupplying different required flows of gas lying between two angularlimit positions, of either of the two different types of gas, N gas orLP gas, the tap having a dual means for limiting the angle of rotationof the regulating organ, and the control knob being interchangeable onthe actuating shaft, which depending on the type of gas used by theappliance can or can not be provided, with a means for guiding therotation in cooperation with a means for limiting the rotation providedon a panel on the cooking appliance.

The gas valve according to the invention is capable of providing twoangular positions of the regulating organ, both spaced apart from eachother to supply a different minimum flow Qmin according to the type ofgas, NG or standard LPG, used as the fuel for the appliance. For thispurpose the regulating organ has two successive Qmin outlet holes spacedapart in the angular direction, which face up individually with theinlet hole in the tap body, being the two different angular positionsestablished by means of a respective rotation stop.

The use of a single valve for regulating the flow of two different gasfamilies is an advantage of the gas valve invention, when mounted on acooking appliance. During the start-up of the cooking appliance the useronly has to carry out a choice for a control knob from among twoavailable units accompanying the valve, in accordance with the type offuel gas NG or LP appropriate for the cooking appliance. Instead ofmounting to each rotary valve shaft one elected class of control knob,the user also can choose for an element of cooker panel, from among twodifferent available units of a panel element to be mounted on thecooker. In this way, it is not necessary to use tools for adjusting theflow, nor to learn how to adjust the regulating organ as is required inthe prior art valve.

DESCRIPTION OF THE DRAWINGS

FIG. 1 is a sectional view of a gas valve fitted on a panel of a cookingappliance according to a first embodiment.

FIG. 2a is a sectional view of the valve regulating organ according tothe line II-II of FIG. 1 with no fluid flow passage being establishedthrough the regulating organ.

FIG. 2b is a sectional view of the valve regulating organ according tothe line II-II of FIG. 1 with a first fluid flow passage establishedthrough the regulating organ.

FIG. 2c is a sectional view of the valve regulating organ according tothe line II-II of FIG. 1 with a second fluid flow passage establishedthrough the regulating organ.

FIG. 3 is a development view of the valve regulating organ of FIG. 2.

FIG. 4 is a front view of the valve installation panel according to FIG.1.

FIG. 5 is a sectional view of a gas valve fitted on a panel of a cookingappliance according to a second embodiment.

FIG. 6 is a perspective view of an element of the panel of cookingappliance in FIG. 5.

FIG. 7 is a schematic diagram of a valve connected to a multi-gasburning appliance.

DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS

With reference to FIGS. 1-4 and 7, a first embodiment of a gas cookingappliance 1A such as a barbecue has an external control panel 2 on whichare mounted one or more rotary gas valves of an existing general type.The cooking appliance 1A, as schematically shown in FIG. 7, may be oftwo types in respect of the type of gas supplied, natural gas (NG) orliquefied gas (LPG) from the external source—GAS IN—through a valveinlet conduit 4 in the valve body 3 a. Each one of the valves 3 mountedon the panel 2 is always of a single type, all with a same valve body 3a and a same frustro-conical regulating organ 6. The inlet flow “Q” istransmitted to an internal chamber 8 in regulating organ 6 incommunication with an outlet conduit 5 in the valve body 3 a. Theregulating organ 6 rotates around a central axis 10 actuated by shaft 7for the supply of the flow “Q”, which is directed towards a burner onthe appliance (not shown in the drawings), being the latter specificallyadapted to either N gas or LP gas.

The valve body 3 a has an elongated shape with a similarlyfrustro-conical central housing cavity 15, wherein the regulating organ6 is pushed by a spring 11 for a tight sealing. The free end of theactuating shaft 7 is installed passing through a hole 2 a in theappliance panel 2, and afterwards the user fits it with a control knob9, which is chosen from the two different units of control knob 9, bothsupplied to the user with each valve unit 3. A cover 12 protecting thehousing cavity 15, has a tubular portion 12 b for guiding the actuatingshaft 7 in rotation.

The regulating organ 6 may rotate with the shaft 7 an angle “A” ineither of the two directions from an initial angular “OFF” positioncorresponding to the valve closed condition, to an angle A larger than180.degree. and smaller than 360.degree. The OFF position is the initialend of the rotational travel “A”, and it is established by a radial pin13 on the shaft. The cover 12 presents a sliding surface for the radialpin 13, extending in a rotating arc “A3” ending in a recess 12 a in thecover, which acts as a stop for the rotation of the radial pin 13.

FIGS. 2 and 3 show an example of the rotary valve 3 used in bothembodiments 1A and 1B of cooking appliances described here. From theangular position OFF rotating in a clockwise direction, thefrustro-conical organ 6 may regulate the supply of different gas flows,a maximum flow “Qmax”, a minimum “Qmin” and an intermediate flow “Qint”between the Qmax and the Qmin, in function of the angle rotated “A”. Aconstant minimum flow “Qmin” of the N gas must be higher than a “Qmin”of the LP gas, when supplied to a respective burner in both cases of thesame power.

Depending on whether N or LP gas is supplied to the cooking appliance,the control knob 9 to be fitted on the actuating shaft 7 isdistinguished by means of an appendix 14 integral with the control knob.A first class of control knob 9 to be chosen for incorporating to eachvalve rotary shaft before being mounted on the appliance 1A, representedon FIG. 1, is adapted for the supply of N gas, being provided thereforewith a protuberance or appendix 14 projecting from a knob base 9 afacing the panel 2. A second class of control knob 9 lacks in having theprotuberance 14 (not shown in the drawings), then the choice forsupplying the gas LPB is chosen in order to be mounted on a cookingappliance 1A for supplying gas LPG. In this case, the control knob 9 canbe rotated up to an angle “A3” greater than the limit position A2 forthe knob unit 9 provided with the protuberance 14. The angular limit A3to the position of the regulating organ 6 depicted in FIG. 3, is imposedby said radial pin 13 stopping against said recess 12 a in the valvecover 12.

In reference to FIGS. 2 and 3, the regulating organ 6 rotates to anangular position A1=90 degrees, for the supply of a maximum flow “Qmax”of either NG or LPG on both types of cooking appliance 1. In thisangular position A1, the Qmax inflow is regulated by a through hole 16in the regulating organ, facing the inlet conduit 4. If the regulatingorgan 6 is rotated further, an intermediate flow “Qint” will be suppliedby way of an ensuing flow opening 17 in the form of a groove which has adecreasing area. Being substantially lower than the Qmax, the “Qint”flow is diminishing in accordance with the angle A rotated, until athrough hole 18 for a “Qmin” flow is facing the inlet conduit 4 at ancorrespondent angular position A2=210 degrees. The diameter D1 of thishole 18 is calibrated for the supply of a Qmin of NG.

On the NG type cooking appliance, the knob class provided with theappendix 14 cannot turn through an angle larger than A2. The externalcontrol panel 2 (FIG. 4) has a circular groove 20 travelled by saidappendix 14 of the knob 9. Its angular extension A2=210 degrees imposesthe limit of angular travel governing the regulating organ 6, from theOFF position to the outlet of the NG Qmin flow by way of hole 18.

Once installed on the panel 2, the knob unit 9 chosen for the supply ofLPG, lacks in having said appendix 14 or any other element limiting theangle “A” of rotation. Thus, the regulating organ 6 may rotate as far asan angular position A3=270 degrees, located farther away from theinitial OFF position than the prior position “A2”, until a secondthrough hole 19 lines up with the inlet conduit 4. The diameter D2 ofhole 19 is calibrated for the supply of a predetermined LPG “Qmin” flow.

It is preferred that the control knob 9 button impose a rotational endposition A2 less than the end position A3 imposed by the actuating shaft7, 13, because the valve body is constructed according to the existingmodel with a limit A3=270.degree. of rotation of the shaft 7, radial pin13 already imposed. The angular values are indicated herein as anexample. Similarly, the regulating valve 3 and its rotary regulatingorgan 6 may be constructed with through holes 16-19, superimposed forthe regulation of the flow “Q” to the outlet conduit 5 of the valveinstead of the inlet conduit 4 as shown in FIG. 2.

The cover 12 of the valve body is equipped with a tubular part 12 b forguiding the actuating shaft of the valve 7 and the recess 12 a to limitthe angular stroke A3=270 degrees corresponding to the Qmin of LPG. Thecover 12 can be made at a low cost using die-stamping operations. Themould for the two different classes of control knob 9, provided with andlacking the guide means 14 can also be made inexpensively by plasticmolding.

The placement of the two stop means 12 a and 20, respectively in thevalve body 3 a and in the control or assembly panel 2 of the appliance1A, each one of them with a pre-determined circular extension,corresponds with the two angular travels A3 and A2. The angular spaceA3-A2 existing between them corresponds to the intermediate spacebetween the two orifices of passage 18 and 19, which are calibrated fora constant Qmin of NG and LPG, respectively. Hence, the same valve unit3 is valid for either of the two types of gas supplied to the cookingappliance 1A, without the need for any adjustment or change in theregulating organ 6 for the supply of another type of gas.

With reference to FIG. 5 and FIG. 6, a second preferred embodiment ofthe cooking appliance 1B is described below, with one or more rotaryvalves 3 mounted on an external panel 2′ of the appliance. The rotaryvalves 3 comprising an actuating shaft 7 with a radial pin 13, aregulator organ 6 such as the one represented in FIG. 2 and FIG. 3, anda control knob 9 having a base 9 a and a guide means or appendix 14, arecommon to the first embodiment 1A represented in FIG. 1 described above.In this second embodiment 1B of the cooking appliance, the externalassembly panel 2′ is adapted as a control panel that includes a bezeldisk 22 for encircling the control knob 9, which is fixed to an opening2 a′ on the visible face of the external or control panel. The bezeldisk 22 is of the type used in the prior art, for the purpose ofembellishing having an indicator dial of said angular positions, OFF,A1, A2, A3 of the regulating organ 6, and forms part of the panel 2′.The bezel disk 22 is crossed through by one end of the actuating shaft 7of the respective valve, having a central recess 22 a housing the base 9a of the knob.

The bezel disk 22 is provided with a stop means 24 for the rotation ofthe control knob 9. The stop means 24 protrudes toward the guide means14 at the base 9 a of the knob, and is constructed preferably of atongue 24 lifted from a cut-off in the surface of the recess 22 a, asshown in FIG. 6. The rotation guide means 14 hits against the tongue 24when it has rotated to the limit position “A2” (FIG. 3) of the regulatororgan 6 corresponding to a Qmin flow supply of natural gas NG. In the“off” position of the valve, the appendix 14 rests on a boss 23 in thecentral recess 22 a, thus the space apart from the boss 23 up to thetongue 24 is the angular travel A2. A second type of bezel disk 22 lacksin having the tongue 24 for the travel stop “A2” (not represented in thedrawings). It is also provided to the user of the cooking appliance 1B,to be chosen for the supply of a flow “Qmin” of LPG gas, by which therotation limit “A” is imposed only by the radial pin 13 of the shaft 7,until the second limit position “A3” of the regulating organ 6, throughthe calibrated orifice 19 in the regulator organ 6 (FIG. 2). Accordingto the second embodiment 1B, the user assembles, for either the supplyof NG or LPG, the same type of control knob 9 equipped with an appendix14, but a bezel disk 22 provided with or lacking the rotation stoptongue 24 respectively.

Other embodiments of the invention in addition to those 1A and 1Bdescribed above are also possible. Either a half of the control knob 9units those of the class provided with a rotation guide means 14, or ahalf of the panel element units 22 those of equipped with a stop means24, will be chosen to be assembled in an appliance 1A or 1B of the typefor supplying the gas NG, said guide means 14 interacting with a stopmeans 20 or 22 on the fixed part of the cooking appliance. On the otherhand, the appliance to be supplied either with the gas LPG will beequipped either with a knob unit 9 of the half lacking the rotationguide means 14, or with a panel element unit 22 of the half lacking thestop means 24.

Likewise, another rotation guide means of the shaft 7 different than theradial pin 13 described here can be constructed for the supply positionA3 of Qmin of LPG through the calibrated orifice 19, interacting with atravel stop in the body 3 a also different from the recess 12 a in thecover 12 herein described. The cooking appliance 1A,1B is alwaysequipped with identical rotary valves 3 for either the supply of NG orLPG, only chosen the class of control knob 9 provided with or lackingthe rotation guide means 14, or chosen the panel element unit 22provided with or lacking the rotation stop means 24.

What is claimed is:
 1. A gas cooking appliance capable of selectivelyusing one of a natural gas and a liquefied petroleum gas, the gascooking appliance comprising: a burner; and a fluid flow controllerhaving a housing with a rotatable organ disposed therein, the rotatableorgan coupled and rotatable with an actuating shaft that extends fromthe housing, the fluid flow controller capable of assuming at least afirst flow configuration and a second flow configuration, the first flowconfiguration being established when the rotatable organ is in a firstangular position, the second flow configuration being established whenthe rotatable organ is in a second angular position that is differentfrom the first angular position, upon assuming the first flowconfiguration a first fluid flow path is established through therotatable organ of the fluid flow controller through a first throughhole passage calibrated to provide a minimum flow rate of the naturalgas to the burner, and upon assuming the second flow configuration asecond fluid flow path is established through the rotatable organ of thefluid flow controller through a second through hole passage calibratedto provide a minimum flow rate of the liquefied petroleum gas to theburner.
 2. A gas cooking appliance according to claim 1, wherein thesecond angular position is successive to the first angular position. 3.A gas cooking appliance according to claim 2, further comprising a stopthat limits the rotation of the rotatable organ to the first angularposition and prevents the rotation of the rotatable organ to the secondangular position.
 4. A gas cooking appliance capable of selectivelyusing one of a natural gas and a liquefied petroleum gas, the gascooking appliance comprising: a burner: and a fluid flow controllerhaving a housing with a rotatable organ disposed therein, the rotatableorgan coupled and rotatable with an actuating shaft that extends fromthe housing, the fluid flow controller capable of assuming at least afirst flow configuration and a second flow configuration, the first flowconfiguration being established when the rotatable organ is in a firstangular position, the second flow configuration being established whenthe rotatable organ is in a second angular position that is differentfrom the first angular position, upon assuming the first flowconfiguration a first fluid flow path is established through therotatable organ of the fluid flow controller through a first throughhole passage having a first diameter to provide a minimum flow rate ofthe natural gas to the burner, and upon assuming the second flowconfiguration a second fluid flow path is established through therotatable organ of the fluid flow controller through a second throughhole passage having a second diameter to provide a minimum flow rate ofthe liquefied petroleum gas to the burner, the second diameter beingsmaller than the first diameter.
 5. A gas cooking appliance according toclaim 4, wherein the second angular position is successive to the firstangular position.
 6. A gas cooking appliance according to claim 5,further comprising a stop that limits the rotation of the rotatableorgan to the first angular position and prevents the rotation of therotatable organ to the second angular position.
 7. A fluid flowcontroller for selectively supplying one of a natural gas and aliquefied petroleum gas to a burner of a gas cooking appliance, thefluid flow controller comprising: a housing; an actuating shaft thatextends from the housing; and a rotatable organ disposed within thehousing, the rotatable organ coupled and rotatable with the actuatingshaft, wherein the fluid flow controller is capable of assuming at leasta first flow configuration and a second flow configuration, the firstflow configuration being established when the rotatable organ is in afirst angular position, the second flow configuration being establishedwhen the rotatable organ is in a second angular position that isdifferent from the first angular position, and wherein upon assuming thefirst flow configuration a first fluid flow path is established throughthe rotatable organ of the fluid flow controller through a first throughhole passage calibrated to provide a minimum flow rate of the naturalgas to the burner, and upon assuming the second flow configuration asecond fluid flow path is established through the rotatable organ of thefluid flow controller through a second through hole passage calibratedto provide a minimum flow rate of the liquefied petroleum gas to theburner.
 8. A fluid flow controller according to claim 7, wherein thesecond angular position is successive to the first angular position. 9.A fluid flow controller according to claim 8, further comprising a stopthat limits the rotation of the rotatable organ to the first angularposition and prevents the rotation of the rotatable organ to the secondangular position.